This invention relates to improving the efficiency of internal combustion engines, particularly those used in motor vehicles.
Through most of the useful range of speeds of a motor vehicle maximum fuel efficiency would be achieved if the engine could be operated at full throttle. An internal combustion engine is essentially a constant torque device. Widely varying road conditions make the combination of a constant torque and constant speed a most unwelcome combination for good efficiency. The best the industry has been able to do so far is to provide the engine with the highest usable torque and vary the gear ratio from the engine to the drive wheels to accommodate the vehicle to changes in load called for by the varying roadway.
With an internal combustion engine (IC engine) the piston and cylinder walls and the like are alternately exposed to widely differing temperatures from as high as 2000 to 3000 degrees F. to exhaust temperatures of about 1000 degrees, or desirably less. Since the change in temperature is related to the engine speed (RPMs), it is clear that the thermal effects become worse at low speeds than at high speeds. This can only result in loss of fuel efficiency at low speeds. The case of automobiles is further obfuscated by the fact that gasoline and diesel fuels require different treatment.
It is possible in the present state of the art economically to provide a servo mechanism fuel control loop which seeks to optimize fuel efficiency with varying speed and varying road conditions. Hence one must contrive two variable displacement pumps, one for gasoline that varies the fuel-air ratio, and the other that varies the charge injected into the cylinder of a Diesel engine--two quite different problems.
In the past the varying solutions proposed to these problems have been obscured by the fact that the optimum fuel charge for best efficiency depends not only upon the compression but upon the temperature, the velocity (swirling), the humidity, the cylinder wall and/or piston head temperature and other fine structure effects too numerous to mention. Prior workers have attempted to include as many of these effects as possible, but have never quite succeeded.
The present invention proposes a much simpler approach to the solution of the problems just enumerated, and, properly engineered, should yield improvement in fuel economy by a factor of at least two over the nearest competition, and perhaps much more.